Mines are devices, which are designed to explode when they are either touched by, or come into close proximity with, an object, such as a vehicle or human beings, causing damage to the object. Landmines are mines which are situated in or on ground terrain. Anti-personnel (AP) landmines are landmines that are specifically designed to harm human beings who are walking or otherwise moving across ground terrain. Mines targeted primarily at vehicles like tanks and troop carriers typically have a diameter in the range of about 20-40 cm. AP mines are typically smaller having for example, a diameter in the range of about 4.5-15 cm. AP mines are often deployed over a large area and are usually buried in the ground or otherwise camouflaged.
The clearing of existing minefields requires special protection for professional de-miners. Common mine injuries include loss of limbs, wounds due to fragmentation devices, and severe injuries to hands, arms, faces, and heads. The latter injuries usually occur when handling a mine, specifically during de-mining. Most accidents and injuries occur during excavation and due to missed mines (See for example: Bergeron D M and Chichester C (2003) Protecting Deminers From APLs: A Review of U.S./Canada Cooperation in R&D. Journal of Mine Action 7.1)
One way of protecting persons, particularly professional de-miners, is to provide some kind of protective footgear that a person can wear when they are in an area known to possibly have mines in the ground. There are basically two types of known protective foot gear: (a) footgear which attempts to provide some shielding action to try to minimise injuries when a mine explodes underfoot; and (b) footgear which is designed to minimise the prospect of mine detonation.
Types of known footgear in the latter category include: (1) air cushion shoes, which distribute the ground reaction force over a large area and thus reduce the pressure applied to a mine (U.S. Pat. No. 4,611,411 to Ringler et al.; U.S. Pat. No. 6,751,892 to Chavet et al.); and (2) metal detector shoes that employ a muscle stimulation effect, such that any metal contact causes an electric impulse to stimulate a muscle, usually a leg muscle, which when stimulated is activated and moves the leg off and away from the mine (U.S. Pat. No. 6,621,418 to Cayrol).
However, the known systems all suffer from significant defects or drawbacks. For example, detonation provoking mine shoes (See U.S. Pat. No. 5,926,977 to Sanders; U.S. Pat. No. 5,979,081 to Vaz; U.S. Pat. No. 5,992,056 to Lohrmann; U.S. Pat. No. 6,006,646 to Makris et al.; U.S. Pat. No. 6,505,421 to Vaz; U.S. Pat. No. 6,655,051 to Peche et al.; U.S. Pat. No. 6,725,572 to Krstic; Patent document SE470498 dated June. 1994 to Bramsell; Patent document DE4402465, dated March. 1995 to Rösner et al.; Patent document no. CN1265464 to Li et al.; PCT document WO03037125 dated May 2003 to Zeman et al.; PCT document WO03101234 dated December 2003 to Joynt et al.; Aigis Engineering Solutions. Available: http://www.aigis.co.uk/; Wellco. Available: http://www.wellco.com/html/blast_protective_boot.html; Kejo Ltd Company. Available: http://bodyarmour.safeshopper.com/79/852.htm?735) are generally damaged and destroyed on explosion of a mine. Hence they are for single use and leave the wearer without appropriate foot gear in the middle of a minefield. Moreover, test results (LEAP 99-2 report: Volume II-Final Report of the Lower Extremity Assessment Program (LEAP 99-2), August 2000 (U.S. Army Communications—Electronics Command, Night Vision Electronic Sensors Directorate, U.S. Army Institute of Surgical Research Extremity, Trauma Study Branch U.S. Army Aberdeen Test Center, U.S. Army Soldier Systems Command). Available: http://www.humanitarian-demining.org/demining/pubs/protection/leap99-2/leap99 2_report_vol 2. asp)) of different mine shoes clearly show, that a person will still at least suffer from broken foot bones, which do not allow the injured person to walk and to leave the mine field without assistance. Most tests (LEAP 99-2 report), however, resulted in injuries, which require treatment such as by amputation (below-knee and above-knee amputations), despite being equipped with blast protection shoes.
So-called detonation preventing air cushion shoes will often not distribute the load sufficiently to reliably avoid a detonation. On uneven ground like woodland, forested lands, and rocky terrain, air cushion shoes can generally not be employed. Furthermore, walking is difficult with such large air cushions on a person's feet. Additionally, puncturing of the cushions causing leakage and loss of air, is a problem, even if the shoe consists of two independent air cushion layers.
Detonation preventing footgear employing muscle stimulating devices also have significant drawbacks. The muscle stimulating devices bypass the normal physiological innervation (nervous supply) of a muscle, and activate the muscle by an electric impulse. Consequently, the central nervous system loses control over the muscle, and the external stimulation results into uncoordinated movements, creates a danger of falling (possibly on the mine), and results in a disturbance to the person's concentration due to the electric shock which activates the muscle.
Accordingly, an improved mine avoidance and protection device is desired.